Make SURE that no one is using the database and that ANALYZE will not begin to run while you are backing up the database. Use any backup utility to copy the DATA, LABELS, and USERS directories.
See Chuck Kollars web site for further suggestions and a sample .BAT file to secure and backup the database.
Some VSS administrators have SUGGESTED using SSARC as a way to backup the database. Use SSARC -d- <archive file> $/ to archive without deleting any files.